The present invention relates to an upper vehicle-body structure of a vehicle which considers an input of a large load from a vehicle side.
US Patent Application Publication No. 2016/0129944 discloses, as the above-described upper vehicle-body structure of the vehicle, a vehicle-body structure which comprises right-and-left center pillars provided at both-side portions of the vehicle, right-and-left roof side rails extending in a longitudinal direction of the vehicle above the right-and-left center pillars, and a roof reinforcement provided at the same positions, in a vehicle-body longitudinal direction, as the center pillars and interconnecting the right-and-left roof side rails in a vehicle width direction.
In the above-described vehicle body, a gusset is attached over the roof reinforcement and the roof side rail so that a load inputted to the center pillar from the vehicle side is transmitted to the roof reinforcement by way of this gusset. Thereby, this load is effectively dispersed to the roof reinforcement, so that it is suppressed that the center pillar comes into a cabin side.
However, according to the vehicle-body structure disclosed in the above-described patent document, even though the center pillar is prevented from coming into the cabin side greatly when a large load (i.e., a load having a specified magnitude or greater), such as an impact load which occurs in a vehicle side collision, is inputted from the vehicle side, the roof side rail may be rotated such that its lower portion is turned toward the vehicle inside in accordance with vehicle-inward deformation of an upper portion of the center pillar, a bending moment to cause a joint portion of the gusset to the roof reinforcement to move upward may occur because of the above-described rotation of the roof side rail, and the amount of load-transmission to the roof side rail and the center pillar, which are positioned on the side where the above-described load is not inputted, may decrease. Consequently, the load inputted to a door or a vehicle-body constituting member located longitudinally adjacently to the door may increase. Thus, while some countermeasures for improving the strength of the door or the vehicle-body constituting member located longitudinally adjacently to the door have been considered, there is room for further improvement in the load transmission with the roof reinforcement.
Herein, it may be considered, as a means for preventing the upward deformation of the roof reinforcement in order to improve the load transmission with the roof reinforcement, that the plate thickness of the roof reinforcement is increased or its cross section is enlarged in the vehicle-body longitudinal direction or in the vertical direction, thereby attaining a rigidity increase of the roof reinforcement. However, there is a concern that these may cause a vehicle-weight increase or an occupant-space decrease improperly.